Background of the Invention.

reportActive / Technical Report | Accession Number: ADD015708 | Need Help?

Abstract:

Acoustic ringing and adverse effects from variations in the NQR detection of explosives and narcotics are minimized or eliminated. A specimen is irradiated with a modified steady state steady state free precession SSFP pulse sequence which combines a phase-alternated pulse sequence PAPS with a non-phase-alternated pulse sequence NPAPS. The resulting signals from the PAS and NPAS may then be coadded to cancel out the FID contributions to the signals. By canceling out the FID contributions to the signals, the effects of probe ringing and other extraneous responses, as well as the effect of temperature variation, are minimized or removed. The present method is especially effective in the detection of explosives and narcotics having 14N or 35,37Cl nuclei. A steady state free precession pulse which is especially useful with the method of the present invention is the strong off-resonance comb SORC. In another embodiment of the invention, the effects of probe ringing can also be minimized or removed by repeating the detection procedure at a frequency which is sufficiently off-resonance so that only frequently independent effects, such as probe-ringing, can be observed

Author(s):
Buess, M. L. ; Garroway, A. N. ; Yesinowski, J. P.
Author Organization(s):
DEPARTMENT OF THE NAVY WASHINGTON DC
Descriptive Note:
Patent Application, Filed 30 Nov 92,
Pagination:
0033

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
PAT-APPL-983 990
Monitor Series:
ONR
 Subject Terms
Joint Capability Areas:
JCA_3.2_Engagement; JCA_3_Force Application; JCA_3.2.1_Kinetic Means
Communities of Interest:
No COI(s) Identified
Descriptor(s):
*PATENT APPLICATIONS, *ACOUSTIC DETECTION, RINGS, EXPLOSIVES, NARCOTICS, STEADY STATE, PROBES
Field(s)/Group(s):
Acoustic Detection and Detectors
Report Date:
1992 Nov 30